Dennis Murphy spends a lot of time on the phone.
"What I'm doing is, I'm calling, I have a list here who haven't been in for a couple of years for their medical screening for the World Trade Center," he said.
As a volunteer for the Word Trade Center Health Program, Murphy reminds 9/11 first responders to stay on top of their health. His calls are polite, but they come with a jarring warning: Anyone who breathed the air at the World Trade Center site 17 years ago may be at risk today.
"I've kind of become an expert on this," he said. "Unfortunately, I've got cancer. As of yesterday, I had cancer in five places. Now, they're telling me I have it in seven places."
Just an hour earlier, Murphy was sitting in his doctor's office, calmly absorbing news of a potentially devastating setback, that the cancer he's been fighting for 17 months probably has spread to his liver and bones.
For years, Murphy says he went in for annual checkups. At a screening last year, he learned he had stage four tongue cancer, and that it had metastasized to other areas of his body.
"I don't look at this as a setback," he said. "It's just another challenge."
Murphy was an NYPD detective on 9/11. In the months after the terror attack, he was assigned to the main city morgue, but shuttled back and forth to the smoldering rubble of the Twin Towers to retrieve human remains. The air, he says, was thick and dirty. At one point, the U.S. Environmental Protection Agency said there was no-long term health risk. First responders like Murphy soldiered on, often without masks.
"Unfortunately, it was something we weren't concerned with," he said. "We had something to do, and the thing we had to do was to recover and give families closure.
The air they breathed and the debris they touched, contaminated by everything from asbestos to tiny glass fibers, may now be making them sick.
The World Trade Center Health Program says 10,086 people, including nearly 8,100 first responders, have developed cancer believed to be the result of 9/11.
"We do see that these are more aggressive tumors," said Dr. Nagashree Seetharamu, an oncologist with the Northwell Health Cancer Institute.
Through it all, Murphy has not dwelled on his situation. The calls, he says, are a form of therapy.
"Yes, this helps a lot," Murphy said. "Because anybody else that I can help, it works well."
It also doesn't hurt that the 56-year-old now-retired detective always tries to stay optimistic.
"I am a tenacious, obstinate, never-give-up Irish cop to heart," Murphy said.
An officer who is fighting for his own life and trying to save others.